9. One Big PCB

  My first prototype is made up of several boards connected with flying leads.  Big and messy.  This needed to be reined in.  The idea is to combine all the circuits that are duplicated for each voice onto one board per voice.  Then all the control voltage inputs from the control panel can be daisy chained to each voice and the voice outputs sent to the final mixer.

  One problem - Eagle PCB limits the board size to 4" x 3" (unless you buy a pro license which is out of my budget), not nearly large enough.  So the switch was made to another PCB tool, DesignSpark PCB.  This is a free tool that doesn't have the limitations of the free version of Eagle, most notably for me, the board size and number of schematic sheets.  Not quite as refined as Eagle but seems to do the job so far.  I did end up importing most of the libraries I was using from Eagle instead of using the DesignSpark libraries.

  So now all the schematics need to be re-entered into DesignSpark and laid out.  Slow and steady to avoid mistakes.  Considering how much is going into one board, I don't want to have a trouble shooting nightmare on my hands.

  I've also decided to modify the original circuits to substitute SMD where I can.  This along with redoing the layouts gives me the opportunity to try and reduce the overall size of the board.


  1. DesignSpark PCB didn't work out quite as well as I thought it would and I ended up going through several different tools trying to find one that works the way I want. So I was kind of spinning my wheels for about a month there. I think I have it sorted out now but have have to reenter the schematics which will take some time. I'll hopefully have an update in a few more weeks, though I may have a little "intermission" project update first ;)